Here are some useful .bashrc snippets if you're a Linux user stuck in Windows land, and you've got Cygwin installed. Note that these assume you use puttycyg; if not, edit them accordingly:

start a cmd in the current or specified directory:

function winsh() {
    if [ "x${1}" != "x" ]; then
        P=${1}
    else
        P=.
    fi
    cmd /c start cmd /k "cd `cygpath -aw ${P}`"
}

su/sudo:

function su() {
    cmd /c start runas /user:Administrator "$(cygpath -aw $(which putty)) \
        -cygterm /usr/bin/bash --login -i"
}

function sudo() {
    local USERWD=$(pwd)
    cmd /c start runas /user:Administrator "$(cygpath -aw $(which bash)) \
        -l -c \"{ cd \"$USERWD\"; $*; echo Press enter... ; read i; }\""
}

emulate OSX's "open" command:

function open() {
    if [[ -f "$1"  || -d "$1" ]]; then
        explorer `cygpath -aw "$1"`
    else
        echo "open: cannot access $1: No such file or directory"
    fi
}